1. Field Of The Invention
The present invention pertains to a self cleaning animal guard for preventing animals from gaining access to the interior of a drain pipe while allowing water including leaves, sticks and debris to exit the pipe substantially unimpeded. More particularly, the present invention pertains to a tamper proof animal guard that is self purging, inexpensive to manufacture, readily installed in the field and efficient in allowing water, at various discharge rates which may or may not include debris, to flow freely and unimpeded out of the drain pipe while preventing rodents and other small animals from obtaining entry to the drain pipe. The invention provides a plurality of individually rotatably mounted pronged wheels which are spaced axially and radially at or near the diameter of the discharge outlet of a drain pipe.
2. Description Of The Prior Art
The prior art includes a variety of devices for preventing animals from gaining access to drain pipes while allowing water and debris to flow out of the drain tile or pipe. The prior art employs various covers, gates and animal stops to prevent the entry of small animals such as rodents, muskrats, raccoons, etc. to the interior of the tile or drain pipe. Such small animals generally become lost in the underground drain pipe and die or build nests which thereafter clog the pipe and require digging up of substantial lengths of drain pipe in order to locate and remove the animal or nest to unclog the drain pipe.
The prior art has employed perforated discs and pronged gate assemblies that have been attached to the inside or outside circumference of the drain pipe. Some of the prior art animal gates and perforated plates have been pivotally actuated by debris present in the discharge water. Such prior art animal guards are susceptible to accidentally remain open by debris lodging between the prongs and the sides of the drain pipe. These prior art animal guards have also been known to have been opened by the more intelligent animals such as raccoons. Other prior art employing gates and plates have been pivotally secured to the end of the drain pipe by means of a pin to prevent the opening of the gate by small animals such as raccoons, but such prior art gates and plates periodically require manual opening to remove leaves, sticks and other debris that build up at the animal guard.
Prior art such as Rue U.S. Pat. No. 906,562 and Miles U.S. Pat. No. 4,356,087 are mounted within the open end of the drain pipe and remain in a closed blocking position to prevent small animals from gaining access to the drain pipe. The flow of drain pipe water containing leaves, sticks and other debris results in the pivoting of the gate open in the direction of flow to allow debris to flow out of the drain pipe. These devices are generally eccentrically mounted with respect to the drain pipe and result in the pivoting of one prong or the entire unit of prongs to allow debris to exit the drain tile or pipe without allowing animals to enter the pipe. These prior art animal guards or drain pipe stops do not employ a plurality of individually mounted rotatable prongs that are self cleaning and tamper proof for preventing rodents or other animals such as raccoons from opening the animal guard while allowing debris and water received from the water inlet to flow out of the animal guard.
Prior art such as Kahn U.S. Pat. No. 3,289,840 pertains to a tamper proof animal guard for preventing small animals from gaining access to drain pipe by providing a pivotable gate which remains closed and is manually opened periodically for cleaning to remove built up debris. This approach to the problem of providing a tamper proof guard for preventing admission of small animals into the drain pipe requires periodic cleaning. Other prior art animal guards that provide pivoting gates have not provided a tamper proof system for preventing the admission of more intelligent animals such as raccoons while providing an inexpensive, low maintenance animal guard that is self purging of sticks, paper, leaves, rags and other debris commonly encountered in drain pipe discharge water. In addition, such prior art pivoting gate guards actuated by debris often results in one or more of the eccentrically mounted pivotal prongs becoming stuck in an open position by debris becoming lodged between one or more of the rods or prongs and the drain pipe resulting from changes in water discharge rates or the clogging of the guard with intermediate sized debris.
The prior art has heretofore not provided an efficient self cleaning and animal tamper proof system for allowing drain pipe water and water containing debris to efficiently pass through the animal guard. The prior art has not employed a plurality of individually rotatable wheels utilizing prongs that rotate at different directions and rates under water flow conditions to provide a self cleaning action and prevent entry of the animals into the drain pipe. The problems of the prior art pivotable gates and prongs result in the lodging of debris in the prong which requires cleaning and can keep the prong or guard in a partially opened position to result in further restriction to flow and the possibility the animal guard will not effectively prevent the admission of animals into the drain pipe.
The devices of the prior art have not provided an efficient self cleaning animal guard that is inexpensive to manufacture, readily assembled and attached to drain pipe outlets to prevent animals from gaining admission to the drain pipe while allowing debris in the pipe to flow out of the drain pipe at various discharge rates. The prior art has sought an animal tamper proof guard having a self cleaning gate or prongs to allow debris to flow out of the drain pipe without becoming lodged in the prongs or gate. The prior art has also sought a device which achieves these advantages at varying flow rates that prevents debris from becoming lodged between the prongs and the drain pipe to result in partially open gates or prongs that subsequently allow the entry of animals.
The novel drain pipe animal guard of the present invention provides an effective tamper proof barrier to keep rodents and small animals from entering the drain pipe while allowing debris and other materials to flow out of the animal guard by preventing sticks, leaves and other debris from becoming entangled in the prongs of the independently rotatable pronged wheels. The present invention, in contrast to the prior art, replaces a pivotally mounted prong or gate with a plurality of axially spaced and individually rotatably mounted pronged wheels radially spaced from the circumference of the drain pipe to prevent the admission of rodents and other small animals to provide an effective tamper proof, self cleaning guard for preventing the admission of raccoons or other intelligent small animals. The novel drain pipe animal guard provides an inexpensive, effective and efficient system for preventing the admission of small animals into the drain pipe that is self cleaning under various rates of flow, by allowing the pronged wheels to individually rotate in a clockwise direction at low water outlet discharge rates and rotate counterclockwise or remain substantially stationary at high water outlet discharge rates. The novel drain pipe guard in the present invention, in addition is a tamper proof animal guard that prevents debris from leaving the prongs or gate in a partially opened position by trapped debris that would allow access for small animals.
The present invention further provides installation and operational advantages over the prior art by the utilization of a plurality of individually rotatable pronged wheels that may conveniently be constructed from plastic and mounted on an axle. The ends of the axle may be mounted to a flexible strap for conforming to a portion of the inside circumference of the drain pipe. A mounting bolt can be utilized and a single hole drilled through the wall of the drain pipe for mounting the strap carrying the axle and rotatable pronged wheels inside the drain pipe. The prongs and mounting strap may be formed from aluminum, galvanized steel or preferably formed from a high density polyethylene or plastic to provide advantages of installation and economy over prior art animal guards. The advantages of the invention are augmented by the novel combination of elements which provides a self cleaning, tamper proof animal guard having advantages not heretofore available in the prior art.